As conventional counterfeit discrimination methods of an iris image, Patent Document 1 and Patent Document 2 disclose methods in which a plurality of near-infrared light sources are selectively lighted and an eye of a living body and a counterfeit eye are discriminated based on a biological reaction of the time-varying iris diameter or positional change of a bright spot caused near the iris.
(Patent Document 1) Japanese Patent No. 3312303
(Patent Document 2) Japanese Patent No. 3315648